Effective glioblastoma immune sonodynamic treatment mediated by macrophage cell membrane cloaked biomimetic nanomedicines.

Glioblastoma (GBM) as one of the most lethal brain tumours, remains poor therapeutic index due to its typical characters including heterogeneous, severe immune suppression as well as the existence of blood brain barrier (BBB). Immune sonodynamic (ISD) therapy combines noninvasive sonodynamic therapy with immunotherapy, which has great prospects for the combinational treatment of GBM. Herein, we develop macrophage cell membrane cloaked reactive oxygen species (ROS) responsive biomimetic nanoparticles, co-delivering of sonosensitizer Ce6 and JQ1 (a bromo-domain protein 4 (BRD4) inhibitor which can down-regulate PD-L1) and realizing potent GBM ISD therapy. The ApoE peptide decorated macrophage membrane coating endows these biomimetic nanoparticles with low immunogenicity, efficient BBB permeability, prolonged blood circulation half-live and good biocompatibility. The ROS responsive polymeric inner core could be readily degraded as triggered by excessive ROS under the ultrasound once they accumulated in tumour cells, fast release encapsulated drugs. The generation of ROS not only killed tumour cells via sonodynamic therapy, but also induced immunogenic cell death (ICD) and further activated the anti-tumour immune response. The released JQ1 inhibited tumour cell proliferation and augmented the immune activities by inhibiting the PD-L1 expression on the surface of tumour cells. The cascade sonodynamic and immune therapy resulted in significantly improved median survival time in both orthotopic GL261 and PTEN deficient immunosuppressive CT2A GBM mice models. Therefore, our developed biomimetic nanoparticle platform provides a promising combinational therapy strategy to treat immune suppressive GBM.

Gastrodin alleviates premature senescence of vascular endothelial cells by enhancing the Nrf2/HO-1 signalling pathway.

Endothelial dysfunction is an independent risk factor for stroke. The dysfunction of endothelial cells (EC) is closely concerned with EC senescence. Gastrodin (GAS) is an organic compound extracted from the dried root mass of the Orchidaceae plant Gastrodiae gastrodiae. It is used clinically to treat diseases such as vertebrobasilar insufficiency, vestibular neuronitis and vertigo. In the present study, we used hydrogen peroxide (H2 O2 )-induced human umbilical vein endothelial cells (HUVECs) to establish an in vitro EC senescence model and to investigate the role and mechanism of GAS in EC senescence. It's found that H2 O2 -treated HUVECs increased the proportion of senescence-associated ß-galactosidase (SA ß-gal) positive cells and the relative protein expression levels of senescence-associated cyclin p16 and p21. In addition, GAS reduced the proportion of SA ß-gal positive cells and the relative protein expression levels of p16 and p21, and increased the proliferation and migration ability of HUVECs. Meanwhile, GAS increased the expression of the anti-oxidative stress protein HO-1 and its nuclear expression level of Nrf2. The anti-senescence effect of GAS was blocked when HO-1 expression was inhibited by SnPPIX. Furthermore, absence of HO-1 abolished the effect of GAS on HUVEC proliferation and migration. In conclusion, GAS ameliorated H2 O2 -induced cellular senescence and enhanced cell proliferation and migration by enhancing Nrf2/HO-1 signalling in HUVECs. These findings of our study expanded the understanding of GAS pharmacology and suggested that GAS may offer a potential therapeutic agent for stroke.

Influenza-associated neurologic complications in children from an H3N2 outbreak in Shenzhen, China during COVID-19 lockdown.

OBJECTIVES: To identify the characteristics of influenza-associated neurologic complications (INCs) in children from a recent H3N2 outbreak in Shenzhen, China during COVID-19 lockdown. METHODS: A retrospective cohort study of INCs in children hospitalized with H3N2 infection was conducted. RESULTS: From June 01, 2022 to July 01, 2022, 513 children with H3N2 infection were hospitalized and 97 developed INCs. Of the 18 patients with encephalopathy/encephalitis, 13 were previously healthy. Three developed acute necrotizing encephalopathy and two died. Of the 63 patients with febrile seizures, 55 (87%) had simple febrile seizures. Of the 14 patients with an exacerbation of seizure with underlying epilepsy, the seizure symptoms occurred mostly within 24 hours of disease onset (13/14). The comparison of the three groups (encephalopathy/encephalitis, febrile seizure and exacerbation of seizure with underlying epilepsy) reported no significant differences in sex, pre-existing neurologic diseases, vaccination rate, white blood cell count, C-reactive protein, procalcitonin, blood glucose, lactic acid, or duration of fever. The influenza vaccination rates were generally low (22% vs 32% vs 21%). Patients with encephalopathy/encephalitis had a higher rate of elevated alanine aminotransferase (28% vs 3% vs 0, P = 0.005). CONCLUSION: H3N2-related neurologic complications in children mainly occur early in the disease course. Most patients were previously healthy and unvaccinated against influenza. Elevated alanine aminotransferase is more common in encephalopathy/encephalitis.

Analysis of Clinical Characteristic and Risk Factors for Short-Term Prognosis of Moyamoya Disease with Intraventricular Hemorrhage in Adults.

BACKGROUND: Intraventricular hemorrhage (IVH) is the most common type of hemorrhage in moyamoya disease (MMD) with intracerebral hemorrhage (ICH), but the risk factors affecting the short-term prognosis of MMD with IVH in adults are still unclear. METHODS: We retrospectively analyzed patients of MMD with IVH between January 1, 2018 and January 31, 2020 in the First Affiliated Hospital of Zhengzhou University. According to the modified Rankin Scale (mRS) score at 3 months after discharge, the patients were divided into mRS score ≤2 (good prognosis) group and mRS score >2 (poor prognosis) groups. Univariate and multivariate logistics regression analysis was used to analyze the risk factors affecting the short-term prognosis of adult MMD with IVH. RESULTS: Univariable analyses showed that patients in the poor prognosis group had a significantly older age of onset (48.48 ± 8.34 vs. 43.74 ± 5.44 years; P = 0.002), a higher percentage of hypertension (57.97% vs. 33.33%; P = 0.014), a higher percentage of tracheotomy (23.19% vs. 2.56%; P = 0.005), a lower Glasgow Coma Scale (GCS) score (7.90 ± 3.58 vs. 11.19 ± 2.56; P = 0.000), a higher Graeb score (7.46 ± 4.04 vs. 5.23 ± 1.93; P = 0.002), and treatment methods (P = 0.000). Multiple logistic regression analysis showed that the lower GCS score (odds ratio [OR], 1.761; P = 0.001) and higher Graeb score (OR, 1.767; P = 0.002) were independently associated with the poor prognosis of MMD with IVH, and surgery treatment (OR, 0.032; P = 0.000) was independently related to the good prognosis of MMD with IVH. CONCLUSIONS: Among patients with MMD with IVH, the lower GCS score and higher Graeb score are independent risk factors for poor prognosis, whereas in patients with MMD with IVH, surgery treatment acts as a protective factor.

Basigin is necessary for normal decidualization of human uterine stromal cells.

STUDY QUESTION: Does basigin (BSG) regulate human endometrial stromal cell (HESC) decidualization in vitro? SUMMARY ANSWER: BSG regulates HESCs proliferation and decidualization. WHAT IS KNOWN ALREADY: Studies have shown that in the human endometrium, BSG expression is menstrual-cycle dependent and its expression was significantly lower in uterine endometrium during the luteal phase of women experiencing multiple implantation failures after IVF than in women with normal fertility. STUDY DESIGN, SIZE, DURATION: We utilized a telomerase-immortalized HESCs in an in vitro cell culture model system to investigate whether BSG regulates decidualization of stromal cells. Further, we used microarray analysis to identify changes in the gene expression profile of HESCs treated with BSG small interfering RNA (siRNA). All experiments were repeated at least three times. PARTICIPANTS/MATERIALS, SETTING, METHODS: The effect of BSG knockdown (using siRNA) on HESC proliferation was determined by counting cell number and by tritiated thymidine incorporation assays. The effect of BSG on decidualization of HESCs was determined by RT-qPCR for the decidualization markers insulin-like growth factor-binding protein 1 (IGFBP1) and prolactin (PRL). Immunoblotting was used to determine the effect of BSG siRNA on the expression of MMP-2,3. Microarray analysis was used to identify BSG-regulated genes in HESCs at Day 6 of decidualization. Functional and pathway enrichment analyses were then carried out on the differentially expressed genes (DEGs). The STRING online database was used to analyze protein-protein interaction (PPI) between DEG-encoded proteins, and CytoScape software was used to visualize the interaction. MCODE and CytoHubba were used to construct functional modules and screen hub genes separately. Several BSG-regulated genes identified in the microarray analysis were confirmed by qPCR. MAIN RESULTS AND THE ROLE OF CHANCE: Knockdown of BSG expression in cultured stromal cells by siRNA significantly (P < 0.05) inhibited HESC proliferation, disrupted cell decidualization and down-regulated MMP-2 and MMP-3 expression. Microarray analysis identified 721 genes that were down-regulated, and 484 genes up-regulated with P < 0.05 in BSG siRNA treated HESCs. GO term enrichment analysis showed that the DEGs were significantly enriched in cell communication, signaling transduction and regulation, response to stimulus, cell adhesion, anatomical structure morphogenesis, extracellular matrix organization, as well as other functional pathways. KEGG pathway analysis identified upregulated gene enriched in pathways such as the MAPK signaling pathway, colorectal cancer, melanoma and axon guidance. In contrast, downregulated genes were mainly enriched in pathways including ECM-receptor interaction, PI3K-Akt signaling pathway, pathways in cancer, antigen processing, type I diabetes mellitus and focal adhesion. The top 10 hub nodes were identified using 12 methods analyses. The hub genes that showed up in two methods were screened out. Among these genes, upregulated genes included EGFR, HSP90AA1, CCND1, PXN, PRKACB, MGAT4A, EVA1A, LGALS1, STC2, HSPA4; downregulated genes included WNT4/5, FOXO1, CDK1, PIK3R1, IGF1, JAK2, LAMB1, ITGAV, HGF, MXRA8, TMEM132A, UBE2C, QSOX1, ERBB2, GNB4, HSP90B1, LAMB2, LAMC1 and ITGA1. Hub genes and module genes involved in the top three modules of PPI analysis were analyzed through the string database. Analysis showed that hub and module genes were related mainly to the WNT signaling pathway, PI3K-AKT signaling pathway and pathways in cancer. LARGE SCALE DATA: The microarray data set generated in this study has been published online at databank.illinois.edu. LIMITATIONS, REASONS FOR CAUTION: Most of the findings were obtained using an in vitro cell culture system that may not necessarily reflect in vivo functions. WIDER IMPLICATIONS OF THE FINDINGS: Our results demonstrate that BSG plays a vital role in decidualization and that downregulation of BSG in the uterine endometrium may be associated with infertility in women. The identified hub genes and pathways increase our understanding of the genetic etiology and molecular mechanisms underlying the regulation of decidualization by BSG. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the NIH U54 HD40093 (R.A.N.). The authors have no competing interests to declare.

Biglycan protects human neuroblastoma cells from nitric oxide-induced death by inhibiting AMPK-mTOR mediated autophagy and intracellular ROS level.

The ubiquitous proteoglycan, biglycan (BGN) acts as an important modulator, regulating key molecular pathways of metabolism and brain function. Autophagy is documented as a defining feature of neurodegeneration in Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). In the present study, we found that BGN protected neuronal cells from nitric oxide (NO)-induced cell apoptosis. However, it is still unclear that whether the neuroprotective effect of BGN relates to autophagy. Here, we discovered that an NO donor, sodium nitroprusside (SNP) induced autophagy in human SH-SY5Y neuroblastoma cells, including activating LC3B and inhibiting p62. Inhibiting autophagy by 3MA aggravated NO-induced cell death, otherwise promoting autophagy by Rapamycin rescued NO-triggered cell death. Notably, BGN downregulated by NO, significantly protected SH-SY5Y cells against NO-induced neurotoxicity by inhibiting the activation of autophagy-dependent AMPK signaling pathway. Moreover, BGN overexpression also diminished NO-induced the elevation of intracellular reactive oxygen species (ROS) level, but not NO content. These findings suggest that BGN protects neuroblastoma cells from NO-induced death by suppressing autophagy-dependent AMPK-mTOR signaling and intracellular ROS level.

NCAM regulates the proliferation, apoptosis, autophagy, EMT, and migration of human melanoma cells via the Src/Akt/mTOR/cofilin signaling pathway.

The neural cell adhesion molecule (NCAM) plays critical roles in multiple cellular processes in neural cells, mesenchymal stem cells, and various cancer cells. However, the effect and mechanism of NCAM in human melanoma cells are still unclear. In this study, we found that NCAM regulated the proliferation, apoptosis, autophagy, migration, and epithelial-to-mesenchymal transition of human melanoma cells by determining the biological behavior of NCAM knockdown A375 and M102 human melanoma cells. Further studies revealed that NCAM knockdown impaired the organization of actin cytoskeleton and reduced the phosphorylation of cofilin, an actin-cleaving protein. When cells were transfected with cofilin S3A (dephosphorylated cofilin), biological behavior similar to that of NCAM knockdown cells was observed. Research on the underlying molecular mechanism showed that NCAM knockdown suppressed activation of the Src/Akt/mTOR pathway. Specific inhibitors of Src and PI3K/Akt were employed to further verify the relationship between Src/Akt/mTOR signaling and cofilin, and the results showed that the phosphorylation level of cofilin decreased following inhibition of the Src/Akt/mTOR pathway. These results indicated that NCAM may regulate the proliferation, apoptosis, autophagy, migration, and epithelial-to-mesenchymal transition of human melanoma cells via the Src/Akt/mTOR/cofilin pathway-mediated dynamics of actin cytoskeleton.

Neural cell adhesion molecule regulates chondrocyte hypertrophy in chondrogenic differentiation and experimental osteoarthritis.

Chondrocyte hypertrophy-like change is an important pathological process of osteoarthritis (OA), but the mechanism remains largely unknown. Neural cell adhesion molecule (NCAM) is highly expressed and involved in the chondrocyte differentiation of mesenchymal stem cells (MSCs). In this study, we found that NCAM deficiency accelerates chondrocyte hypertrophy in articular cartilage and growth plate of OA mice. NCAM deficiency leads to hypertrophic chondrocyte differentiation in both murine MSCs and chondrogenic cells, in which extracellular signal-regulated kinase (ERK) signaling plays an important role. Moreover, NCAM expression is downregulated in an interleukin-1ß-stimulated OA cellular model and monosodium iodoacetate-induced OA rats. Overexpression of NCAM substantially inhibits hypertrophic differentiation in the OA cellular model. In conclusion, NCAM could inhibit hypertrophic chondrocyte differentiation of MSCs by inhibiting ERK signaling and reduce chondrocyte hypertrophy in experimental OA model, suggesting the potential utility of NCAM as a novel therapeutic target for alleviating chondrocyte hypertrophy of OA.

Celastrol Induces Necroptosis and Ameliorates Inflammation via Targeting Biglycan in Human Gastric Carcinoma.

Celastrol, a triterpene isolated from the root of traditional Chinese medicine Thunder of God Vine, possesses anti-cancer and anti-inflammatory activity to treat rheumatoid disease or as health product. Necroptosis is considered as a new approach to overcome chemotherapeutics resistance. However, whether celastrol exerts necroptosis leading to gastric cancer cell death is still unclear. Here, for the first time we showed that celastrol induced necroptosis in HGC27 and AGS gastric cancer cell lines. More importantly, celastrol down-regulated biglycan (BGN) protein, which is critical for gastric cancer migration and invasion. Furthermore, celastrol activated receptor-interacting protein 1 and 3 (RIP1 and RIP3) and subsequently promoted the translation of mixed-lineage kinase domain-like (MLKL) from cytoplasm to plasma membrane, leading to necroptosis of gastric cancer cell, which was blocked by over-expression BGN. In addition, celastrol suppressed the release of pro-inflammatory cytokines TNF-α and IL-8 in HGC27 and AGS cells, which was reversed by over-expression BGN. Taken together, we identified celastrol as a necroptosis inducer, activated RIP1/RIP3/MLKL pathway and suppressed the level of pro-inflammatory cytokines by down-regulating BGN in HGC-27 and AGS cells, which supported the feasibility of celastrol in gastric cancer therapy.

Lipid rafts regulate the lamellipodia formation of melanoma A375 cells via actin cytoskeleton-mediated recruitment of ß1 and ß3 integrin.

Lipid rafts, distinct liquid-ordered plasma membrane microdomains, have been shown to regulate tumor cell migration by internalizing and recycling cell-surface proteins. The present study reports that lipid rafts are a prerequisite for lamellipodia formation, which is the first step in the processes of tumor cell migration. The results from the wound-healing assay and immunostaining indicated that lipid rafts were asymmetrically distributed to the leading edge of migrating melanoma A375 cells during lamellipodia formation. When the integrity of lipids rafts was disrupted, lamellipodia formation was inhibited. The investigation of possible molecular mechanisms indicated that lipid rafts recruited ß1 and ß3 integrins, two important adhesion proteins for cell migration, to the lamellipodia. However, the different distribution characteristics of ß1 and ß3 integrins implied disparate functions in lamellipodia formation. Further immunostaining experiments showed that the actin cytoskeleton was responsible for lipid raft-mediated ß1 and ß3 integrin distribution in the lamellipodia. Together, these findings provide novel insights into the regulation of lipid rafts in lamellipodia formation, and suggest that lipid rafts may be novel and attractive targets for cancer therapy.

Biglycan, a Nitric Oxide-Downregulated Proteoglycan, Prevents Nitric Oxide-Induced Neuronal Cell Apoptosis via Targeting Erk1/2 and p38 Signaling Pathways.

Nitric oxide (NO), a gaseous signaling molecule, induces apoptosis and mediates neurodegenerative diseases and brain injury. Biglycan (BGN), a member of the small leucine-rich proteoglycan family, was demonstrated to exert anti-apoptosis function in various disease models. However, little is known about the effect of BGN on NO-induced neurotoxicity. Here, for the first time, we reported that BGN protects against NO-induced apoptosis in human neuroblastoma SH-EP1 cells. This is supported by the finding that sodium nitroprusside (SNP), a NO donor, triggered downregulation of BGN in SH-EP1 cells, and over-expression of BGN strikingly attenuated NO-induced nuclear fragmentation and apoptosis of neuronal cells. More importantly, BGN remarkably blocked NO-induced phosphorylation of Erk1/2 and p38 signaling, but not JNK MAPK pathway in neuronal cells. Furthermore, inhibiting Erk1/2 by U0126 or p38 by SB203580 partially protected against NO-induced cell death. Conversely, downregulation of BGN by siRNA aggravated NO-induced neuronal cell death, which was not attenuated by U0126 or SB203580. These findings indicated that BGN, downregulated by NO, prevents NO-induced neuronal cell apoptosis via targeting Erk1/2 and p38 signaling pathways. Our results strongly suggest that BGN could be explored for the prevention of NO-induced neurodegenerative disorders.

ANXA2 could act as a moderator of EGFR-directed therapy resistance in triple negative breast cancer.

Triple negative breast cancer (TNBC) patients cannot benefit from EGFR-targeted therapy even though the EGFR is highly expressed, because patients exhibit resistance to these drugs. Unfortunately, the molecular mechanisms remain relatively unknown. ANXA2, highly expressed in invasive breast cancer cells, is closely related with poor prognosis, and acts as a molecular switch to EGFR activation. In this study, MDA-MB-231 cells and MCF7 cells were used. Our results showed that ANXA2 expression is inversely correlated with cell sensitivity to gefitinib. Knockdown of ANXA2 expression in MDA-MB-231 cells increased the gefitinib induced cell death. When ANXA2 was overexpressed in MCF7 cells, the gefitinib induced cell death was decreased. Furthermore, we demonstrated that phosphorylation of ANXA2 at Tyr23 is negatively correlated with the sensitivity of TNBC to gefitinib. Altogether, our results suggest a new role of ANXA2 in regulating sensitivity of TNBC MDA-MB-231 cells to the EGFR inhibitor gefitinib.

NCAM affects directional lamellipodia formation of BMSCs via ß1 integrin signal-mediated cofilin activity.

The neural cell adhesion molecule (NCAM), a key member of the immunoglobulin-like CAM family, was reported to regulate the migration of bone marrow-derived mesenchymal stem cells (BMSCs). However, the detailed cellular behaviors including lamellipodia formation in the initial step of directional migration remain largely unknown. In the present study, we reported that NCAM affects the lamellipodia formation of BMSCs. Using BMSCs from Ncam knockout mice we found that Ncam deficiency significantly impaired the migration and the directional lamellipodia formation of BMSCs. Further studies revealed that Ncam knockout decreased the activity of cofilin, an actin-cleaving protein, which was involved in directional protrusions. To explore the molecular mechanisms involved, we examined protein tyrosine phosphorylation levels in Ncam knockout BMSCs by phosphotyrosine peptide array analyses, and found that the tyrosine phosphorylation level of ß1 integrin, a protein upstream of cofilin, was greatly upregulated in Ncam-deficient BMSCs. Notably, by blocking the function of ß1 integrin with RGD peptide or ROCK inhibitor, the cofilin activity and directional lamellipodia formation of Ncam knockout BMSCs could be rescued. Finally, we found that the effect of NCAM on tyrosine phosphorylation of ß1 integrin was independent of the fibroblast growth factor receptor. These results indicated that NCAM regulates directional lamellipodia formation of BMSCs through ß1 integrin signal-mediated cofilin activity.

PRDM5 promotes the proliferation and invasion of murine melanoma cells through up-regulating JNK expression.

PRDM (PRDI-BF1 and RIZ domain-containing) proteins constitute a family of zinc finger proteins and play important roles in multiple cellular processes by acting as epigenetic modifiers. PRDM5 is a recently identified member of the PRDM family and may function as a tumor suppressor in several types of cancer. However, the role of PRDM5 in murine melanoma remains largely unknown. In our study, effect of PRDM5 on murine melanoma cells was determined and results showed that PRDM5 overexpression significantly promoted proliferation, migration, and invasion of murine melanoma B16F10 cells. Consistently, silencing of PRDM5 expression significantly inhibited proliferation, invasion, and migration of B16F10 cells. In vivo study also showed that PRDM5 silencing significantly inhibited the growth and metastasis of melanoma in mice. PRDM5 was then found to increase the expression and activation of JNK in B16F10 cells. JNK silencing significantly reduced PRDM5-mediated up-regulation of JNK expression and blocked the PRDM5-induced proliferation and invasion of B16F10 cells. To further verify the involvement of JNK signaling in PRDM5-induced progression of B16F10 cells, a specific JNK inhibitor was employed to inhibit the JNK signaling pathway, and results showed that PRDM5-induced proliferation and invasion of B16F10 cells were abolished. We conclude that PRDM5 promotes the proliferation and invasion of murine melanoma cells through up-regulating JNK expression and strategies targeting PRDM5 may be promising for the therapy of melanoma.

Sequence variants on chromosome 9p21 are associated with ischemic stroke and the lipids level in Chinese Han population.

BACKGROUND: Several studies have demonstrated that variants on chromosome 9p21 confer susceptibility to ischemic stroke (IS) disease. But, the results of variants' roles in Chinese IS population are blank or inconsistent. METHODS: We performed a case-control analysis in 116 patients with IS and 118 non-IS controls of Han background to determine whether 4 single nucleotide polymorphisms were associated with IS. DNA was extracted from saliva using a magnetic nanoparticles-based method. RESULTS: After we adjusted for clinical parameters, we found that the rs10757278-GG genotype conveyed 1.88-fold (95% confidence interval [CI], 1.1-3.1; P = .015), the rs1537378-C allele conveyed 2.0-fold (95% CI, 1.2-3.5; P = .008), and the rs1333047-TT genotype conveyed 1.64-fold (95% CI, 1.02-2.6; P = .041) increased risk of IS, respectively. In addition, there is a significant difference of the lipids level between GG genotype compared with that of AA genotype in rs10757278 (P < .05). CONCLUSIONS: This study is the first one to demonstrate that the rs10757278-GG genotype, the rs1537378-C allele, and rs1333047-TT genotype are associated with IS in Chinese Han populations. More importantly, the variant of rs10757278 may have different degrees of influence on lipids level.

Effects of integrins and integrin αvß3 inhibitor on angiogenesis in cerebral ischemic stroke.

Integrins such as αvß3, α5ß1 play a key role in angiogenesis regulation, invasion and metastasis, inflammation, wound healing, etc. The up-regulation of integrin αvß3 after cerebral ischemic stroke can promote angiogenesis, which in turn improves functional recovery. In addition, the integrin αvß3 inhibitor can block the blood-brain barrier (BBB) leakage induced by vascular endothelial growth factor (VEGF) and also can reduce inflammatory reaction, decrease the deposition of fibrinogen. Other studies showed that integrin αvß3 is not essential in revascularization. Therefore, the effect of integrin αvß3 in the whole process of brain function recovery merits further study.

Identification of nucleolin as a lipid-raft-dependent ß1-integrin-interacting protein in A375 cell migration.

Lipid rafts are related to cell surface receptor function. Integrin is a major surface receptor protein in cell adhesion and migration on the extracellular matrix (ECM). Here, we showed that lipid rafts played a critical role in human melanoma A375 cell spreading and migration on fibronectin; an important component of the ECM that interacts with ß1 integrin. We found that the disruption of lipid rafts did not markedly inhibit the expression and activation of ß1 integrin. By coimmunoprecipitation and mass spectrometry, we investigated the influence of lipid rafts on the ß1 integrin complex and identified nucleolin as a potential lipid-raft-dependent ß1-integrin-interacting protein. Upon confirmation of the interaction between ß1 integrin and nucleolin, further studies revealed that nucleolin colocalized with ß1 integrin in lipid rafts and raft disruption interrupted their association. In addition, knockdown of nucleolin markedly attenuated A375 cell spreading and migration on fibronectin. Taken together, we demonstrated that nucleolin is a critical lipid-raft-dependent ß1-integrin-interacting protein in A375 cell spreading and migration on fibronectin.

Extracellular matrix collagen alters cell proliferation and cell cycle progression of human uterine leiomyoma smooth muscle cells.

Uterine leiomyomas (ULs) are benign tumors occurring in the majority of reproductive aged women. Despite the high prevalence of these tumors, little is known about their etiology. A hallmark of ULs is the excessive deposition of extracellular matrix (ECM), primarily collagens. Collagens are known to modulate cell behavior and function singularly or through interactions with integrins and growth factor-mediated mitogenic pathways. To better understand the pathogenesis of ULs and the role of ECM collagens in their growth, we investigated the interaction of leiomyoma smooth muscle cells (LSMCs) with two different forms of collagen, non-polymerized collagen (monomeric) and polymerized collagen (fibrillar), in the absence or presence of platelet-derived growth factor (PDGF), an abundant growth factor in ULs. Primary cultures of human LSMCS from symptomatic patients were grown on these two different collagen matrices and their morphology, cytoskeletal organization, cellular proliferation, and signaling pathways were evaluated. Our results showed that LSMCs had distinct morphologies on the different collagen matrices and their basal as well as PDGF-stimulated proliferation varied on these matrices. These differences in proliferation were accompanied by changes in cell cycle progression and p21, an inhibitory cell cycle protein. In addition we found alterations in the phosphorylation of focal adhesion kinase, cytoskeletal reorganization, and activation of the mitogen activated protein kinase (MAPK) signaling pathway. In conclusion, our results demonstrate a direct effect of ECM on the proliferation of LSMCs through interplay between the collagen matrix and the PDGF-stimulated MAPK pathway. In addition, these findings will pave the way for identifying novel therapeutic approaches for ULs that target ECM proteins and their signaling pathways in ULs.

Lipid rafts control human melanoma cell migration by regulating focal adhesion disassembly.

Tumor cell migration is a crucial step in the metastatic cascade, and interruption of this step is considered to be logically effective in preventing tumor metastasis. Lipid rafts, distinct liquid ordered plasma membrane microdomains, have been shown to influence cancer cell migration, but the underlying mechanisms are still not well understood. Here, we report that lipid rafts regulate the dynamics of actin cytoskeleton and focal adhesion in human melanoma cell migration. Disrupting the integrity of lipid rafts with methyl-ß cyclodextrin enhances actin stress fiber formation and inhibits focal adhesion disassembly, accompanied with alterations in cell morphology. Furthermore, actin cytoskeleton, rather than microtubules, mediates the lipid raft-dependent focal adhesion disassembly by regulating the dephosphorylation of focal adhesion proteins and the internalization of ß3 integrin. We also show that Src-RhoA-Rho kinase signaling pathway is responsible for lipid raft disruption-induced stress fiber formation. Taken together, these observations provide a new mechanism to further explain how lipid rafts regulate the migration of melanoma cell and suggest that lipid rafts may be novel and attractive targets for cancer therapy.

Basigin null mutant male mice are sterile and exhibit impaired interactions between germ cells and Sertoli cells.

Basigin (BSG) is a multifunctional glycoprotein that plays an important role in male reproduction since male knockout (KO) mice are sterile. The Bsg KO testis lacks elongated spermatids and mature spermatozoa, a phenotype similar to that of alpha-mannosidase IIx (MX) KO mice. MX regulates formation of N-acetylglucosamine (GlcNAc) terminated N-glycans that participate in germ cell-Sertoli cell adhesion. Results showed that Bsg KO spermatocytes displayed normal homologous chromosome synapsis and progression through meiosis. However, only punctate expression of the round spermatid marker SP-10 in the acrosomal granule of germ cells of Bsg KO mice was detected indicating that spermatogenesis in Bsg KO mice was arrested at the early round spermatid stages. We observed a large increase in the number of germ cells undergoing apoptosis in Bsg KO testes. Using lectin blotting, we determined that GlcNAc terminated N-glycans are linked to BSG. GlcNAc terminated N-glycans were significantly reduced in Bsg KO testes. These observations indicate that BSG may act as a germ cell-Sertoli cell attachment molecule. Loss of BSG significantly reduced adhesion between GC-2 and SF7 cells. Moreover, wild type testes showed strong expression of N-cadherin (CDH2) while expression was greatly reduced in the testes of Bsg KO mice. In addition, the integrity of the blood-testis barrier (BTB) was compromised in Bsg KO testes. In conclusion, although some Bsg KO spermatogonia can undergo normal progression to the spermatocyte stage, BSG-mediated germ cell-Sertoli cell interactions appear to be necessary for integrity of the BTB and spermatocyte progression to mature spermatozoa.